CNC cutting files for fabricators
https://www.theboilershop.com.au/
Curvo-mark: https://www.weldclass.com.au/tag/1-brand/value/546-curv-o-mark
Flange wizard: http://flangewizard.com/
All pipe fab needs: https://pipefitter.com/
In this short video lecturer Glen Jones explains techniques used by fabricators to align pipes, flanges and elbows.